الفهرس 
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Abstract
A number of substituted dihydropyrimidine and 1,3,4-oxadiazole based
pyrimidine nucleus as their as their sugar derivatives were synthesized.
1,3-bis(4-bromophenyl)-2,3-epoxypropanone (2) was prepared by treatment
of 1,3-bis(4-bromo phenyl) propenone (1) with hydrogen peroxide in alkaline
medium.
Reaction of 2 with thiourea in alcoholic potassium hydroxide, produced the
tetrahydropyrimidin-5-one derivative 3
Reaction of 3 with 2,3,4-tri-O-acetyl-D-xylopyranoside afforded the
thioxylosyl derivative 4Deacetylation of the O-acetyl thioglucoside 4 afforded the free thioglycosidederivative 5Compound 2 was reacted with urea and/or thiosemicarbazide to give the
substituted tetrahydropyrimidine derivatives 6 and 7, resThe thiazolo[3,2-a]pyrimidine-3,6-dione 8 was prepared by reacting 3 with
chloroacetic acid in acetic acid / acetic anhydride mixture.
Thethiazolo[3,2-a] pyrimidine-3,6-dione 9 was directly prepared from
compound 3 in one step by heating with chloroacetic acid and benzaldehyde in
acetic acid/acetic anhydride mixture in the presence of sodium acetate. Compound
9 was also prepared from compound 8 by reaction with benzaldehyde